Can anyone comment on quality differences between older versions of LAME in terms of its 320kbps CBR encoding?

I am cleaning my library and I suppose I am looking for a cutoff point to shoot for in terms of quality. I have some 3.82, 3.89b, 3.90, etc. Most of my music is LAME3.97 and above... but should I replace my older MP3's?

Thanks. Yeah I came across this page on my own but didn't find many references to 320 CBR encoding. Most of the changes involve things that don't concern me. Concerning 320 it does mention a bit reservoir for a couple of releases and fixing padding. I just don't know enough to understand significance.

3.98.4 is a landmark version, with the subsequent versions having different psy and vbr tuning.Some members have expressed their opinion that 3.98.4 is their preferred version of LAME, I believe during threads discussing disadvantages in the newer tuning implementations.

I thinbk what (s?)he meant was "keep everything newer than 3.90". But it is an ambiguous statement.

I did a double-take on that phrasing too, but the OP asked about replacing 320 kbps CBR MP3s; the recommendation is to keep, i.e. do not replace, those that were encoded with post-3.90 versions of LAME.

I'd add that prior to version 3.99, CBR files at bitrates under 192 kbps needed nonstandard -q values (7, 8 or 9) to dodge the issue in bug tracker item 3187397. The initial report and some unrelated testing I did for gapless issues both revealed that 128 kbps encodes were especially susceptible to a risk of audible artifacts.

Of course, I wouldn't worry about redoing any files whatsoever, if they don't actually sound bad.

I also second the recommendation of just going to lossless once and for all if peace-of-mind is really an issue, rather than upgrading every time there's a potential quality improvement in LAME (all those red lines in the changelog). You can store 2000+ FLAC-encoded albums per terabyte, and 3-TB external drives are ~$125 now...

Thanks for the information everyone. Will take the recommendation of only replacing MP3's older than LAME 3.90. Like I have said, this is a tiny proportion of my music collection so it will not be a big deal. (It is actually just a single album by Desmond Dekker... so no biggie AT ALL, easy to fix.)

Very much considering going lossless. At least for my favorite albums. Can't really go lossless when it comes to a lot of rap and hip-hop that is only released via online mixtapes for free. I listen to a wide variety of music, but it is probably more important for keeping lossless quality when it comes to classical, rock, alternative, etc... simply because there are real instruments to be heard.

I also don't have an out of this world sound system, so not really worth all that extra hard drive space to have FLAC since I probably can't tell with my speaker setup. But some day. All subjective and relative blah blah blah. I should invest in some amazing headphones I am thinking... like beats audio, haha jk.

Very much considering going lossless. At least for my favorite albums. Can't really go lossless when it comes to a lot of rap and hip-hop that is only released via online mixtapes for free. I listen to a wide variety of music, but it is probably more important for keeping lossless quality when it comes to classical, rock, alternative, etc... simply because there are real instruments to be heard.

I also don't have an out of this world sound system, so not really worth all that extra hard drive space to have FLAC since I probably can't tell with my speaker setup. But some day. All subjective and relative blah blah blah. I should invest in some amazing headphones I am thinking... like beats audio, haha jk.

Hard drive space is cheap nowadays; you can get a 3TB drive for less than $130 -- that's over 4000 CDs worth of space, if you ripped them all to Wav instead of Flac.

Several years ago when I got my first computer of my own (I had a 30GB hard drive), I was ripping my CDs to 160 CBR using whatever ripping program came with my computer; I couldn't tell the difference on my setup at the time. The next year my CD wallet, containing my entire collection, was stolen from my car. When I got my next new set of speakers, suddenly I could hear all the artifacts in my MP3s, and I was very disappointed. Since then, I've always ripped all of my CDs to Flac, regardless of whether I can tell the difference.

However, since I also own an MP3 player with a very limited storage capacity (2GB), I wrote a program called FlacSquisher to handle the encoding so I can use Oggs or MP3s on those devices. Then I have my Flac archive, and my Ogg or MP3 copies for mobile use. Then if I want to use a new version of Lame or a different bitrate, I can just delete my lossy folder and start over. If I was only going to have my MP3 copy I'd probably use -V0, but since I don't I'm perfectly happy using -V4 for casual listening in noisy environments like the gym, so that means I can fit a wider array of music on my MP3 player.